In recent years subscribers have been using cell phones in more technologically diverse environments. Subscribers use mobile phones in circuit switched environments, packet switched environments, Wi-Fi environments as well as other environments. Dual mode service (DMS), that is, use of a phone in a Wi-Fi environment as well as other cellular environments, has become more popular. Wi-Fi access points are plentiful in industry (e.g., coffee shops, airports, hotels) as well as at home. With the advent of Internet Protocol (IP) Multimedia Subsystem (IMS) networks, dual mode subscribers may use their mobile phones in both Wi-Fi and cellular networks. DMS calls across IMS networks and cellular networks have to be anchored in an IMS network. This anchoring requires adding a new service control point (SCP) or service control function (SCF) element to the IMS network (as per VCC). The additional SCF/SCP used to support DMS, however, is not integrated on the same platform as existing Intelligent Networking (IN) services. Offering IN services across separate SCF/SCPs may lead to trigger contention.
A need exists, therefore, for a way to address trigger contention issues that arise when a DMS subscriber wants to access their existing IN services across cellular and IMS networks.